Transparent pavement.



L. G. MULLEN.

TRANSPARENT PAVEMENT.

APPLlCATlON FILED JAN. 7. 1915.

Patented Apr. 25,1916.

WWW,

THE coLUMmA PLANOGRAPH co, WASHINGTON, D. c

. E A. Tl l LEO Gr. MULLEN, 0F PITTSBURGH, PENNSYLVANIA.

TRANSPARENT PAVEMENT.

Application filed January 7, 1915.

To all whom it may concern Be it known that I, LEO G. MULLEN, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Transparent Pavements, of which the following is a specification.

This invention relates to that class of glass paving blocks which are used in luminous floors or transparent pavements, and it has for its particular object to provide a lens for said pavements which can be removed and replaced or another one substituted should an accident happen to the original lens.

A further particular object is to provide a lens and a metal helix which cooperate to initially position the lens within the pavement or floor, so that, when the lens is re placed, its succeeding position will be identical with the original position.

These and other objects hereinafter mentioned, are accomplished with the means illustrated in the accompanying drawing, in which Figure 1 is a perspective view of one of the improved lenses looking at the lower side thereof. Fig. 2 is a vertical transverse sectional viewof the lens shown in Fig. 1. Fig. 3 is a similar view of Fig. 1 showing in addition the wire helix in place thereon. Fig. 4 is a bottom plan view of one of the lenses showing a modified form. Fig. 5 is a vertical transverse sectional View of one of the lenses and helix in position in a floor or pavement, and Fig. 6 is a similar view to Fig. 5 with the lens removed.

In all of the figures of the drawing, similar reference numerals designate like parts. Referring to the drawing, a part of a concrete floor or pavement is shown at 7 and as seen in Fig. 5, a glass block or lens 8 is shown embedded therein.

In constructing the pavement or floor, a plurality of the blocks are assembled and supported in spaced relation in any suitable manner and the concrete is poured around the same to form the pavement floor. In the present instance, it is desirous of installing the blocks so that they can be removed and replaced. To accomplish this, a wire helix 9 is embedded in the concrete forming a permanent thread which cooperates with the threads 10 on the blocks or lenses, thus making the blocks removable and replace- Specification of Letters Patent.

Patented Apr. 25, rate.

Serial No. 882.

able or a substitute block inserted, should the original block be broken or destroyed.

The metal helix is embedded in the concrete together with the original block, the helix being positioned upon the block, as shown in Fig. 3, before the block is assembled, so that the concrete will flow around both and secure them in place. The metal helix has its ends terminating in laterally extended arms 11, preferably bent toward each other, these arms serving as anchors for the said helix. Thus it will be seen, should a lens be broken or removed by unscrewing it from the metal helix, a new one can be easily substituted or the original one be replaced.

To correctly and accurately position all of the metal helices in the concrete, means is provided on each block for limiting thepassage of the block through the helix, or in other words, selecting the position of the helix on the block, so that, when the blocks are first set to receive the concrete, all of them havin their upper surfaces in the same plane, all of the metal helices will be positioned in the same relation to the upper and lower surfaces of the floor. This correct position of the metal helix on the block, as shown in Fig. 3, is secured by providing an abutment or shoulder 12 in one of the grooves between the integral threads of the block, with which a shoulder 15 on the metal helix engages, or in other words, abruptly terminating the lower end of the helical groove, formed by the threads, short of the lower face of the block, thus forming at the lower end of the block or lens, a head or flange 14 whose periphery lies in a plane with the periphery of the integral. threads and of gradually increasing depth to said. abutment. The shoulder 15 is formed by bending the laterally extending arms ab' ruptly out of the path of the helix as shown.

With this construction, the metal helix can be completely embedded in the concrete floor and in a position which will assure every block, when fully screwed into place, a correct location with its upper face flush with the upper surface of the pavement, and by accomplishing this with the abutting shoulders of the block and the metal helix, the limiting strain is imposed upon the metal helix in alinement with threads and not transverse of the same which would have a tendency of rupturing or displacing the threads. i

In the preferred embodiment, each block is provided with a series or plurality of curved prisms on its lower face, the same projecting slightly below the lower edge of the shoulder or flange it, as clearly shown in Figs. 1, 2 and 3 of the drawings. These prisms deflect the light rays and throw them laterally to illuminate the chamber beneath the floor.

In the modified form of block shown in Figs. 4: and 5, a hexagonal recess is formed in the lower side of the block, the sides of the recess being slightly inclined which serve to some extent as deflectors for the rays of light,.and in both instances, a special tool is provided, which fits between the curved prisms and in the hexagonal recess, respectively, to screw the blocks in place when re placing or substituting.

In operation, the lenses with their metal helices screwed thereon, as shown in Fig. 3, are initially supported in spaced relation with the heads or flanges l l forming the lower sides. The concrete of the floor or pavement is then poured around the lenses and allowed to set. This completes the pavement or floor. N ow should any of the lenses be broken or removed for any cause, a new one can be inserted from the underside of the floor.

By abruptly terminating the helical groove on the lenses within the head or flange, allows the positioning of the abrupt shoulder at the lower end of the metal helix close to the lower surface of the pavement and the heads or flanges form fillers for the space below the, lower coil of the metal helix. This forms a flush finish for the lower side of the floor and does not require pointing up as heretofore done. Furthermore it will be observed that the head at the lower end of the lens projects equally as far as the periphery of the threads, so that, when the lens having the wire helix thereon with their cooperating shoulders in engagement, is cast in a pavement, the threads and head of the lens displaces the plastic material of the pavement from around the inner face of the wire helix, and leaves the same projecting into the lens recess when the lens is removed. The filling head also displaces the plastic material of the pavement below and beyond the end of the wire helix a width greater than the inside diameter thereof and entirely to the underside of the pavement, thus when the lens is removed, the shoulder of the wire helix is left free and unobstructed and permitting a free entrance of the lens.

Thus it will be seen, that the metal threads are not exposed on either surface of the floor, and when a lens is being screwed in place from the underside as described, it is positively known by the operator, when the shoulders on the members contact, that the upper face of the lens is flush with the upper surface of the floor.

111 renewing lenses, it is found preferable to coat the periphery thereof with a waterproofing mixture before inserting them in place. This forms a water-tight joint. It will be further observed, that the upper side of the flange or head 14 forms a continuation of the threads to the shoulder 12, thus the lowermost thread forms the head or flange 14: and serves as the filler to make a flush finish for the under surface of the floor.

Having thus fully described the invention, what is claimed is 1. A device of the character described, comprising a helically threaded lens forming a groove between the threads, said groove being abruptly terminated in a head at one end of the lens to form a shoulder, and a metal helix having an abrupt shoulder thereon to engage the terminal of the groove, said head and the lower end of said thread adapted to displace from around the shoulder of the metal helix the plastic material of the pavement in which the helix and lens is cast.

9. A device of the character described, comprising a helically threaded lens. the lower coil of said thread forming a filling head of gradually increasing width and in which the groove formed by the threads terminates, and a metal helix having an abrupt shoulder to engage against the terminal of said groove, said head and the lower end of said thread adapted to displace from around the shoulder of the metal helix the plastic material of the pavement in which the helix and lens is cast.

In testimonv whereof I aflix my signature in presence of two witnesses.

LEO G. MULLEN.

Witnesses:

CHAS. BERNHARD, H. P. MULLEN.

copies or this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

